Bone and muscles Flashcards
(86 cards)
1
Q
The skeletal system consists of
A
The skeleton (bone and cartilage) and muscles
2
Q
The roles of the skeletal system
A
skeleton gives (protection) and (support) for muscle attachment so organism can move/ The bones (make blood cells) and store calcium/ Muscles produce contractions to give force for (movement)
3
Q
Compact bone makes up the
A
outer layer of the shaft of long bones
4
Q
The compact bone is made up of
A
Haversian systems
5
Q
The name of bone cells
A
osteocytes
6
Q
osteocytes start their lives as
A
osteoblasts
7
Q
The cells responsible for synthesis and deposition of the organic and inorganic substances of the bone matrix
A
osteoblast
8
Q
osteoblasts synthesis and deposit… and ….. to form…
A
tropocollagen fibres and calcium phosphate to form the bone matrix
9
Q
bone is made up of 30% of …. and 60% of…. and 10% of ….
A
organic collagen. inorganic calcium phosphate. osteocytes
10
Q
Haversian systems are made up of
A
lamella
11
Q
The lamella is made up of
A
bone matrix (collagen and calcium phosphate)
12
Q
The spaces in which osteocytes are present in the Haversian system
A
Lacuna
13
Q
Links the lacunae
A
canaliculi
14
Q
the Haversian canal has
A
artery vein and nerve
15
Q
osteocytes in the lacunae maintain contact through
A
through cytoplasmic processes in the canaliculi
16
Q
what’s the point of the nerve, artery and vein in the haversian canal?
A
it supplies the osteocytes with nutrients and oxygen and take away wastes
17
Q
The bone-forming cells
A
osteoblasts
18
Q
The cells that maintain the bone
A
osteocytes
19
Q
The cells that are continuously breaking down bone
A
osteoclasts
20
Q
The coordinated actions of osteoblasts, osteocytes and osteoclasts allow for
A
bone remodeling
21
Q
bone remodeling stimulated due to
A
new stresses such as hormonal changes, activities( mechanical stress stimulate bone formation) and damage
22
Q
Can physical activities change bone formation?
A
mechanical stress on bones can stimulate bone formation in the areas subjected to the increased mechanical stress
23
Q
Normal bone metabolism
A
osteoblast activity= osteoclasts activity
24
Q
osteoporosis bone metabolism
A
osteoclasts activity> osteoblasts activity
25
If cartilage does not have blood vessels how could chondrocytes get nutrients and oxygen
through diffusion of nutrients and oxygen from surrounding tissues
26
The locations of hyaline cartilage
lining the joints, joining ribs and in the trachea
27
The colour of hyaline cartilage
It is translucent
28
The function of chondrocytes
the secretion of proteins
29
Adaptations in the chondrocytes to do their function
well developed endoplasmic reticulum and Golgi body
30
Cartilage is made up of ..... and .....
75% water and 25% collagen and glycoprotein
31
The slippery surface of cartilage is due to
glycoproteins
32
Why is hyaline cartilage present in the joints
due to the chondrocytes well developed ER and Golgi body it secrets proteins to form glycoproteins that will give a slippery surface. The slippery surface is needed for the movement of some joints
33
The case where cartilage break down exceeds cartilage renewal
osteoarthritis
34
All synovial joints have
joint cavities filled with synovial fluid
35
what type of joint is the suture joint
fibrous joint bc of the dense fibrous connective tissue within it
36
the tissue within the cranium suture is
dense fibrous connective tissue d
37
give two types of synovial joints
ball and socket and hinge
38
give a fibrous joint
suture joint (immovable joint)
39
give a cartilage joint
semi-movable joint ( vertebral column)
40
The cartilage within the ball and socket joint of the hip and the hinge joint of the elbow and knee
articular (hyaline cartilage)r cartilage
41
in synovial joint the bone are held together by
collagen capsule
42
ligaments are present in
the capsule
43
ligaments have
high tensile strength
44
the function of the synovial membrane
1- it secrets synovial fluid that lubricate the movement of bones.
2- it detects and removes foreigner bodies from the synovial fluid
3- it provides nutrients to the chondrocytes
45
Articular (hyaline) cartilage function in the joints
it reduces the friction in the joints (it is slippery bc of glycoproteins)
46
Osteoporosis results in
Broken bones and severe postural problems ( wedged upper vertebrae and crushed lower vertebrae)
47
Having a ..... when young reduces the risk of osteoporosis
high mass/ density bone
48
How to achieve high density bone (helps in avoiding osteoporosis)
Exercise regularly- Ensure sufficient calcium and vitamin D in the diet
49
How come menopause is a risk factor for osteoporosis ?
During menopause, the ovaries gradually decrease their production of estrogen, leading to a significant decline in circulating estrogen levels in the body. Estrogen has several effects on bone metabolism, including inhibiting bone resorption (breakdown) by osteoclasts, promoting osteoblast (bone-forming cell) activity, and maintaining the balance between bone formation and resorption. The reduction in estrogen levels disrupts these processes, resulting in increased bone turnover and a net loss of bone density over time.
50
Maximum bone mass at.... , then declines by.... per year
30 . 7%
51
what is osteoporosis
a condition in which so much bone mass is lost that the bones become more likely to break
52
what is the first sign of osteoporosis
breaking of a bone with relatively little cause
53
How come pregnancy is a protective factor against osteoporosis?
- high levels of oestrogen
- increased ca absorption
54
How come high caffeine intake is risk factor for osteoporosis ?
high caffeine intake inhibits the absorption of ca in the intestine. Therefore, less ca will be available in the body and less ca deposit in the bone making the bone less dense
55
How come steroid use is a risk factor for osteoporosis ?
- increases the activity of osteoclasts
- inhibit the activity of osteoblasts
- decrease the absorption of ca in the intestine
56
How come smoking is a risk factor for osteoporosis ?
Smoking interferes with the absorption of calcium in the intestines and decreases the production of estrogen in women, both of which contribute to lower bone density. As a result, smokers tend to have weaker bones compared to non-smokers.
57
Mention the two kinds of arthritis
- rheumatoid arthritis
-osteoarthritis
58
what happens in rheumatoid arthritis
the body's own immune system attack the cartilage
59
What happens in osteoarthritis?
- The articular cartilage degenerates faster than its regeneration as a result cartilage can not cope and fragments
- changes in collagen and glycoprotein content also occur
- resulting pain and loss of joint movement
60
treatment for arthritis
joint replacement surgery
61
factors leading to arthritis
obesity, ageing, injury, sport, and genes
62
The two movements at the elbow joint
-flex
-extend
63
what happens to the joint angle during flexing and extending
- decreases in flexing
- increases in extending
64
biceps and triceps are
an antagonistic pair
65
Muscle is a group of
fibres
66
what surrounds each muscle fibre
sarcolemma
67
within a muscle fibre is
a myofibril
68
surrounds a myofibril is a
sarcoplasmic reticulum
69
striated or skeletal muscles are so called bc of the stripes seen in .......
longitudinal section micrographs
70
A transverse section micrograph of the skeletal muscle will show.....
myofibril end-on
71
The only filaments in the I band
Actin filaments
72
The only filaments in the H band
myosin filaments
73
The filaments within the A band
both actin and myosin filaments
74
Thin filaments are made from the proteins......
actin, tropomyosin and troponin
75
Actin is a...... protein
globular
76
How are the thin filaments made
they are made from the globular protein actin. The protein molecules link to form long chains. Then, long chains get into twisted pairs attached to a membrane called the Z-line. The protein tropomyosin forms long chains in the groove between the actin chains and the protein troponin ( a globular protein) binds to the actin chain at regular intervals.
77
The twisted pairs of actin get attached to.....
the z line
78
the thick filaments are made from....
Myosin
79
How are the thick filaments formed
myosin molecules lying side by side with their heads in a way that they are grouped at the 2 ends of the thick filament. The tails of the filaments are attached to the M line.
80
the...... of the thin and thick filaments is what gives the skeletal muscle the striped appearance
the extreme regularity
81
Muscles contract when
the actin and myosin filaments slide over one another. This causes the sarcomere to shorten and thus the muscle length to shorten.
82
The myosin head has...
ATPase enzyme to break down atp
83
The muscle is relaxed there is ....
no attachment between the myosin heads and the actin
84
Give an account of muscle relaxation
-When muscle is stimulated by. nerve impulse. The calcium ions bind to the troponin in the actin and changes its shape. The troponin moves the tropomyosin away from the myosin head binding sites of the actin.
- The myosin heads hydrolyses the ATP to ADP and P using the enzyme ATPase and the heads become cooked
85
Give an account of the muscle contraction ( you should include the relaxation)
-A nerve impulse trigger the binding of calcium ions to the troponin and changes its shape. Troponin moves away tropomyosin from the myosin head binding sites on the actin
- The myosin heads hydrolyses ATP to ADP and P and become cooked
- A nerve impulse stimulates the muscle and the myosin head binding sites are now available
-The myosin head binds to the actin filament
- after binding the head tilts by 45 degrees causing the actin and myosin to slide over each other, shorten the sarcomere and contracting the muscle
-ADP and P are released and a new ATP is bound
- the presence of ATP allows the head to be detached
- ATP is hydrolysed and the head is cooked again and ready for the next attachment at a binding site further along the actin molecule
- the cycle repeats itself 5x per second until the muscle is no longer stimulated
- when the nerve impulse stops
1- calcium ions release stops and they are pumped back to the sarcoplasmic reticulum
2-Troponin regains its original shape and re-occupies the actin head binding sites, preventing further contractions
86
